Door construction



Oct. 25, 1955 GRANDGENT DOOR CONSTRUCTION Filed April 10, 1952 4 Sheets-Sheet l INVENTOR LOUIS GRANDGENT BY 771W-1 ATTORNEYS Oct. 25, 1955 GRANDGENT DOOR CONSTRUCTION 4 Sheets-Sheet 2 Filed April 10, 1952 INVENTOR LOUIS GRANDGENT BY 92 711 m ATTORNEYS Oct. 25, GRANDGENT DOOR CONSTRUCTION 4 Sheets-Sheet 5 Filed April 10, 1952' INVENTOR LOUIS GRANDGENT ATTORNEYS 1955 GRANDGENT DOOR CONSTRUCTION 4 Sheets-Sheet 4 Filed April 10, 1952 1 '1 Ill llLi INVENTOR LOUIS GRANDGENT C no BY M MM ATTORNEY United States Patent DOOR CONSTRUCTION Louis Grandgent, Atlanta, Ga. Application April 10, 1952, Serial N0. 281,496

6 Claims. or. 160-190) This invention realtes to folding overhead doors, and refers more particularly to an improved door for use in garages, buildings and other structures. Its greatest use is for a door forming an entrance to either a detached or attached garage for residences.

One of the principal objects of the invention is to provide a door of a plurality of sections, preferably at least three sections, each section of which may be entirely counterbalanced at each position of its rotation and travel, by its own counterbalancing mechanism. The counterbalancing means is constant because each door section moves vertically, and the door as a whole is fioatingly suspended during its upward and downward movements, the movements thereof taking place with the barest amount of friction.

A further object isconcerned with the arrangement and location of the sheaves, cables and the attaching means for the cables to individual door sections, the structural design of the sections resulting in a compact nesting of the sections with the uppermost section having a portion located in a sloping projecting position when folded, thus affording protection against rain and snow.

An additional object is to provide an upwardly folding door which in addition to having mechanical merit in that it is compact, virtually weightless'and frictionless, that also meets architectural, structural and space clearance requirements under different installation conditions, and is comparatively cheap to manufacture and install.

Other objects will appear hereinafter throughout the specification.

In the drawings:

Figure l is a front view of the door'in closed. position.

Figure 2 is a rear view, partly broken away of the door shown in Figure 1.

Figure 3 is a side elevation of the .door in partly folded position.

Figure 4' is a perspective view of the rear or back of the door in partly open position as in Figure 3', .partly broken away to show the one of the sheave assemblies and counterbalancing weights at one side of the door.

Figure 5 is a transverse vertical section of the door in folded position.

Figure 6 is a side elevational view of one of the sheave It will be understood that the door may be constructed for a single car entrance garage, or a two or more entrance garage depending on the size of the door opening in which it is installed. It will be further understood that the rack and pinion construction shown and described hereinafter in detail, may optionally be dispensed with, although it is preferred that such rack and pinion construction be used in order to insure the accurate and proper alignment of the door sections in their upward and downward movements. It will be further understood that the crossbars shown along the central axis of each door section in Figure 5 may be optionally dispensed with, although it is preferred that such crossbar be used where the door construction is such as to require a stiffening member.

In the drawings, A indicates the door as a whole. This door comprises a plurality of sections preferably three in number and indicated at 10, 12 and 14. These are hinged to each other by hinges 16 and 18. The upper door section may be provided with a window 20.

As seen in Figure 3 there is a vertical track 22, and horizontal track 24, the latter being located at the extreme upper corner of the door, the former for guiding the up and down movements of all of the sections and the latter for the free edge of the upper door section. The other side of the door is provided with similar tracks.

Each of the door sections is supported for rotative movements by pivot means which moves in the vertical tracks, and the intermediate section is pivoted at its side edges to the upper and lower sections.

Only one side of the door, its mounting means in the door opening and its counterbalancing mechanism have been shown in detail, inasmuch as both sides are alike.

Adjacent the middle portion of the upper section and extending beyond both side edges thereof, is a shaft 26 having on each end thereof a roller 28 which runs in the vertical track 22. The upper edge of the section 10' has a pair of brackets 29 each mounting a pin 30 on which is rotatably mounted a roller 32 which runs in horizontal track 24, as shown in Figures 7 and 9.

'A short rack 34 is attached to each side of the door frame, only one of these being shown to avoid unnecessary illustration. They are however identical, each being mounted adjacent the vertical side edges of the upper door panel when the door is in closed position. Fixedly mounted on the shaft 26 inwardly from each roller 28 on each: end of this shaft is a pinion gear 36 in meshed relation with its rack 34. Figure 10 shows this gear at the top. of its movement with panel 10 in inclined position which is at the extreme position of movement of the panel, the door being fully opened as shown in Figure 5. The purpose of this arrangement is to assure equal and uniform travel of both sides of the door. There is no side thrust to cause binding and resistance to movement. On Well lubricated ways, and with smoothly operating rollers, the door may operate perfectly, but with this rack and gear arrangement, perfect operation at all times is assured.

Asv shown by Figures 2, 3 and 4, the intermediate and lower panels are each provided substantially midway of the height thereof with shafts 38 and 40 each having rollers 42 and 44 on opposite ends thereof, respectively. These rollers run in the vertical tracks 22.

The door sections are counterbalanced by means which counterbalances each section individually as they travel in the tracks and pivot about their centrally located shafts. This. means includes a sheave assembly 46 having three pulleys 48, 50, and 52, one pulley for each door section. When the door is comprised of more than three sections (not shown) a separate pulley or pulley groove is provided for each section. Two such sheave assemblies are provided. The pulleys of each sheave assembly are mounted on shaft 54 supported in the door frame, so that they are in angular relationship, as seen in Figures and 8, whereby the cables extend substantially vertically downward towards the supporting shafts of the door sections.

As seen in Figures 5, 6 and 7, sheave 50 supports a flexible cable 56, which is attached to a U-shaped hanger 58 by means of a slug 60 on the end of the cable, and the other end is attached to the upper weight 62 by means of slug 82 which engages weight bracket 84.

The hanger 58 is permitted free pivotal movement about the shaft 26 upon which it is mounted. Mounted between the furcations of the hanger is a guide or idler pulley 64 for guiding cables to the hangers 66 and 68 which hangers are mounted on door section supporting shafts 38 and 40 respectively. Shaft 38 supports hanger 66 as shown in Figures 4 and 6. These three hangers are identical in construction except that the lowermost hanger 68 does not require a guide pulley such as the pulley 64 shown in Figure 11, as no cables extend below this hanger. The purpose of the guide pulleys is to guide the cable to its hanger.

Cable ends 70 and 72 that are attached to their hangers 66 and 68, and which are trained over sheaves 48, 52 respectively, are actually parts of the same flexible cable which extends downwardly on the other side of the sheaves, and through a passageway 74. This passageway extends vertically through the weight 62. The cable is looped around a pulley 76 mounted by means of a bracket 78 on the upper end of a second weight 80.

While there has been shown a single looped cable and a single Weight for supporting and counterbalancing the intermediate and lower door sections, it will be appreciated that independent or separate cables and/ or weights could be provided to support and counterbalance each of these door sections. The construction shown and above described, however, is preferred because the sections are separately suported and counterbalanced due to the separate cable ends, and considerable space is thus saved. Both weights on each side of the door may be guided by vertical channels 86 formed adjacent the side edges of the door opening.

It will be noted that the manner of pivoting the door sections causes the horizontal center line of each to move in a vertical direction. Thus there is no substantial change in the location of the center of gravity of any section, and therefore no variation in the amount of effort required to open or close the door. The entire weight of the door is moved in a vertical path, along with the center of gravity and in line with the vertical guide ways, and is completely counterbalanced at all times. The shaft pivots and hinge pivots are out of line so that in closed position they form a toggle arrangement rendering the door substantially rigid.

In order to raise the door from outside of the garage the main operating handle 88 is grasped and pulled toward the operator, breaking the toggle formed by the aligned sections of the door, whereupon the door will coast to the open position shown in Figure 5. This is because there is only a small amount of frictional resistance to be overcome, and the folding action of the door sections with their ball bearing rollers in the horizontal and vertical tracks is such that the rotative impulse exerted in breaking the toggle imparts a vertical acceleration to the door sections, initiating an upward movement, and in addition the counterweights may be adjusted to slightly overbalance the weight of the door. The means of suspension of the door is slightly eccentric with reference to the center of gravity when the door approaches its closed position, which results in the positive closure of the door. One of the door sections is provided with a recess 90 for the reception of a locking handle 92. Rotation of the handle may operate through eccentrically connected links which will lock the door in closed position. Such mechanism for locking folding doors is well known and is conventional, except the recessed housing 100 for the handle and its particular location to enable nesting as shown in Figures 1 and 5. Conventional linkage for locks of this general type are disclosed at 33, 36, 38 in the Farr Patent 1,804,329, May 5, 1931 and 26, 28 in the patent to Backes 1,893,263, January 2, 1933.

The door may be lowered from inside or outside the garage by grasping the handle S4 located adjacent the lower end of door section 14.

The lower rail 96 of the upper section is provided with a cut out portion or notch 98.

While it is not desired to limit the invention to materials of a specific description, it is preferred to use cross bars or rails of aluminum alloy of stock section, door facings of plywood. Sheaves having formica pulleys with graphite-bronze bearings, flexible steel aeroplane cable, cast iron counterweights, aluminum alloy shafts, and ball bearing rollers, similar to roller skate wheels.

It will be obvious to those skilled in the art that various changes may be made in my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown in the drawings and described in the specification, but only as indicated by the appended claims.

I claim:

1. The combination of a door frame defining a doorway, a sectional door for closing said doorway and comprising an upper section, an intermediate section and a lower section, guide means on either side of said door frame extending in a vertical direction, means pivotally supporting each door section in the vertical guide means substantially centrally of the height thereof, means pivoting the intermediate section along both longitudinal side edges thereof to one of the longitudinal side edges of the upper, and one of the longitudinal side edges of the lower section, separate counterbalancing means connected to the means for pivotally supporting each door section, said counterbalancing means independently counterbalancing each door section, said means for pivotally supporting each door section including a shaft, rollers on either end of each shaft, cable means connected to the ends of each shaft, a sheave assembly over which said cable means is trained, said cable means comprising a cable connecting the upper door section and its counterbalancing means and other cable means connecting the intermediate and lower sections to their common counterbalancing means.

2. The combination of a door frame defining a doorway, a sectional door for closing said doorway and comprising an upper section, an intermediate section and a lower section, guide means on either side of said door frame extending in a vertical direction, means pivotally supporting each door section in the vertical guide means substantially centrally of the height thereof, means pivoting the intermediate section along both longitudinal side edges thereof to one of the longitudinal side edges of the upper, and one of the longitudinal side edges of the lower section, separate counterbalancing means connected to the means for pivotally supporting each section, said counterbalancing means independently counterbalancing each door section, said means for pivotally supporting each door section including a shaft, rollers on either end of each shaft, cable means connected to the ends of each shaft, a sheave assembly over which said cable means is trained, said cable means comprising a cable connecting the upper door section and its counterbalancing means and other cable means connecting the intermediate and lower sections to their common counterbalancing means, said counterbalancing means comprising a plurality of weights at opposite sides of said door, whereby the entire door moves vertically with substantially no change in the position of the center of gravity of any section.

3. The combination of a door frame defining a doorway, a sectional door for closing said doorway and comprising an upper section, an intermediate section and a lower section, guide means on either side of said door frame extending in a vertical direction, means pivotally supporting each door section in the vertical guide means substantially centrally of the height thereof, means pivoting the intermediate section along both longitudinal side edges thereof to one of the longitudinal side edges of the upper, and one of the longitudinal side edges of the lower section, separate counterbalancing means connected to the means for pivotally supporting each door section, said counterbalancing means independently counterbalancing each door section, said means for pivotally supporting each door section including a shaft, rollers on either end of each shaft, cable means connected to the ends of each shaft, a sheave assembly over which said cable means is trained, said cable means comprising a cable connecting the upper door section and its counterbalancing means and other cable means connecting the intermediate and lower sections to their common counterbalancing means, a plurality of vertical racks mounted on said door frame adjacent to the vertical side edges of the upper section and pinion gears fixedly mounted on the pivotal axis of the upper section adjacent the vertical side edges thereof, said pinion gears being in mesh with said racks.

4. The combination of a door frame defining a doorway, a sectional door for closing said doorway and comprising an upper section, an intermediate section and a lower section, guide means on either side of said door frame extending in a vertical direction, means pivotally supporting each door section in the vertical guide means substantially centrally of the height thereof, means pivoting the intermediate section along both longitudinal side edges thereof to one of the longitudinal side edges of the upper, and one of the longitudinal side edges of the lower section, separate counterbalancing means connected to the means for pivotally supporting each door section, said counterbalancing means independently counterbalancing each door section, said means for pivotally supporting each door section including a shaft, rollers on either end of each shaft, cable means connected to the ends of each shaft, a sheave assembly over which said cable means is trained, said cable means comprising a cable connecting the upper door section and its counterbalancing means and other cable means connecting the intermediate and lower sections to their common counterbalancing means, horizontal tracks on said door frame, said upper section having rollers mounted adjacent the upper corners of said upper section, said last named rollers being in engagement with said horizontal tracks.

5. The combination of claim 4, wherein the upper door section, in folded position, is downwardly and outwardly inclined to provide a drain surface, and the intermediate and lower door sections are parallel and in a substantially horizontal plane.

6. The combination of a door frame defining a doorway, a sectional door for closing said doorway and comprising an upper section, an intermediate section and a lower section, guide means on either side of said door frame extending in a vertical direction, means pivotally supporting each door section in the vertical drive means substantially centrally of the height thereof, means pivoting the intermediate section along both longitudinal side edges thereof to one of the longitudinal side edges of the upper, and one of the longitudinal side edges of the lower section, separate counterbalancing means connected to the means for pivotally supporting the door section, said counterbalancing means independently counterbalancing each door section, said means for pivotally supporting each door section including a shaft, rollers on either end of each shaft, cable means connected to the ends of each shaft, a sheave assembly over which said cable means is trained, said cable means comprising a cable connecting the upper door section and its counterbalancing means and other cable means connecting the intermediate and lower sections to their common counterbalancing means, horizontal tracks on said door frame, said upper section having rollers mounted adjacent the upper corners of said upper section, said last named rollers being in engagement with said horizontal tracks, a plurality of vertical racks mounted on said door frame adjacent to the vertical side edges of the upper section and pinion gears fixedly mounted on the pivotal axis of the upper section adjacent the vertical side edges thereof, said pinion gears being in mesh with said racks.

References Cited in the file of this patent UNITED STATES PATENTS 681,953 Cross Sept. 3,1901 1,653,170 Guilbert, Jr. Dec. 20, 1927 1,706,442 Dautrick Mar. 26,1929 1,833,252 Hayman Nov. 24,1931 1,978,234 Stevens Oct. 23, 1934 2,258,948 Garrison Oct. 14,1941 2,362,789 Workman Nov. 14, 1944 

